/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * Contributors:
 * IBM Corporation - initial API and implementation
 *******************************************************************************/
package cn.elwy.rcp.ui.navigator.internal.resources.actions;

import java.util.Iterator;
import java.util.List;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.FileTransfer;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.SelectionListenerAction;
import org.eclipse.ui.part.ResourceTransfer;

import cn.elwy.rcp.ui.navigator.internal.resources.plugin.WorkbenchNavigatorMessages;

/**
 * Standard action for copying the currently selected resources to the clipboard.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * 
 * @since 2.0
 */
/* package */class CopyAction extends SelectionListenerAction {

  /**
   * The id of this action.
   */
  public static final String ID = PlatformUI.PLUGIN_ID + ".CopyAction"; //$NON-NLS-1$

  /**
   * The shell in which to show any dialogs.
   */
  private Shell shell;

  /**
   * System clipboard
   */
  private Clipboard clipboard;

  /**
   * Associated paste action. May be <code>null</code>
   */
  private PasteAction pasteAction;

  /**
   * Creates a new action.
   * 
   * @param shell the shell for any dialogs
   * @param clipboard a platform clipboard
   */
  public CopyAction(Shell shell, Clipboard clipboard) {
    super(WorkbenchNavigatorMessages.CopyAction_Cop_);
    Assert.isNotNull(shell);
    Assert.isNotNull(clipboard);
    this.shell = shell;
    this.clipboard = clipboard;
    setToolTipText(WorkbenchNavigatorMessages.CopyAction_Copy_selected_resource_s_);
    setId(CopyAction.ID);
    PlatformUI.getWorkbench().getHelpSystem().setHelp(this, "CopyHelpId"); //$NON-NLS-1$
    // TODO INavigatorHelpContextIds.COPY_ACTION);
  }

  /**
   * Creates a new action.
   * 
   * @param shell the shell for any dialogs
   * @param clipboard a platform clipboard
   * @param pasteAction a paste action
   * @since 2.0
   */
  public CopyAction(Shell shell, Clipboard clipboard, PasteAction pasteAction) {
    this(shell, clipboard);
    this.pasteAction = pasteAction;
  }

  /**
   * The <code>CopyAction</code> implementation of this method defined on <code>IAction</code> copies the selected
   * resources to the clipboard.
   */
  public void run() {
    List<?> selectedResources = getSelectedResources();
    IResource[] resources = (IResource[]) selectedResources.toArray(new IResource[selectedResources.size()]);

    // Get the file names and a string representation
    final int length = resources.length;
    int actualLength = 0;
    String[] fileNames = new String[length];
    StringBuffer buf = new StringBuffer();
    for (int i = 0; i < length; i++) {
      IPath location = resources[i].getLocation();
      // location may be null. See bug 29491.
      if (location != null) {
        fileNames[actualLength++] = location.toOSString();
      }
      if (i > 0) {
        buf.append("\n"); //$NON-NLS-1$
      }
      buf.append(resources[i].getName());
    }
    // was one or more of the locations null?
    if (actualLength < length) {
      String[] tempFileNames = fileNames;
      fileNames = new String[actualLength];
      for (int i = 0; i < actualLength; i++) {
        fileNames[i] = tempFileNames[i];
      }
    }
    setClipboard(resources, fileNames, buf.toString());

    // update the enablement of the paste action
    // workaround since the clipboard does not suppot callbacks
    if (pasteAction != null && pasteAction.getStructuredSelection() != null) {
      pasteAction.selectionChanged(pasteAction.getStructuredSelection());
    }
  }

  /**
   * Set the clipboard contents. Prompt to retry if clipboard is busy.
   * 
   * @param resources the resources to copy to the clipboard
   * @param fileNames file names of the resources to copy to the clipboard
   * @param names string representation of all names
   */
  private void setClipboard(IResource[] resources, String[] fileNames, String names) {
    try {
      // set the clipboard contents
      if (fileNames.length > 0) {
        clipboard.setContents(new Object[] { resources, fileNames, names },
            new Transfer[] { ResourceTransfer.getInstance(), FileTransfer.getInstance(), TextTransfer.getInstance() });
      } else {
        clipboard.setContents(new Object[] { resources, names }, new Transfer[] { ResourceTransfer.getInstance(),
            TextTransfer.getInstance() });
      }
    } catch (SWTError e) {
      if (e.code != DND.ERROR_CANNOT_SET_CLIPBOARD) {
        throw e;
      }
      if (MessageDialog.openQuestion(shell, "Problem with copy title", // TODO ResourceNavigatorMessages.CopyToClipboardProblemDialog_title,  //$NON-NLS-1$
          "Problem with copy.")) { //$NON-NLS-1$
        setClipboard(resources, fileNames, names);
      }
    }
  }

  /**
   * The <code>CopyAction</code> implementation of this <code>SelectionListenerAction</code> method enables this action
   * if one or more resources of compatible types are selected.
   */
  protected boolean updateSelection(IStructuredSelection selection) {
    if (!super.updateSelection(selection)) {
      return false;
    }

    if (getSelectedNonResources().size() > 0) {
      return false;
    }

    List<?> selectedResources = getSelectedResources();
    if (selectedResources.size() == 0) {
      return false;
    }

    boolean projSelected = selectionIsOfType(IResource.PROJECT);
    boolean fileFoldersSelected = selectionIsOfType(IResource.FILE | IResource.FOLDER);
    if (!projSelected && !fileFoldersSelected) {
      return false;
    }

    // selection must be homogeneous
    if (projSelected && fileFoldersSelected) {
      return false;
    }

    // must have a common parent
    IContainer firstParent = ((IResource) selectedResources.get(0)).getParent();
    if (firstParent == null) {
      return false;
    }

    Iterator<?> resourcesEnum = selectedResources.iterator();
    while (resourcesEnum.hasNext()) {
      IResource currentResource = (IResource) resourcesEnum.next();
      if (!currentResource.getParent().equals(firstParent)) {
        return false;
      }
      // resource location must exist
      if (currentResource.getLocationURI() == null) {
        return false;
      }
    }
    return true;
  }

}
